1. Field of the Invention
The invention relates to an inflatable bed, more particularly to an inflatable bed that can be produced at a relatively low cost.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional inflatable bed 200 is shown to comprise upper and lower mattress portions 7 which are heat-sealed to each other. Each mattress portion 7 has top and bottom sheets 71, 72, and an upstanding peripheral wall 74 that is bonded to peripheral portions of the top and bottom sheets 71, 72 by heat-sealing process so as to define an air inflatable chamber. Each mattress portion 7 includes a plurality of tensile members 73 heat-sealed to the top and bottom sheets 71, 72. Two annular sheets 75 are heat-sealed to the lower mattress portion 7 so as to form a first auxiliary air chamber 201 that surrounds a bottom end of the upper mattress portion 7, thereby positioning the mattress portions 7 relative to each other. Two opposite sides of the lower mattress portion 7 are heat-sealed respectively with a pair of lateral sheets 76 so as to form second auxiliary air chambers 202, thereby increasing the contact area of the lower mattress portion 7 relative to a ground surface, and thereby consequently positioning the conventional inflatable bed 200 on the ground surface.
However, the manufacturing cost of the conventional inflatable bed 200 is relatively high since aside from the materials used for producing the two mattress portions 7, additional material is required for the annular sheets 75 and the lateral sheets 76 as well. Furthermore, the conventional inflatable bed 200 is difficult to fabricate.
Referring to FIGS. 3 and 4, another conventional inflatable bed 200xe2x80x2 is shown to include a top sheet 71xe2x80x2, a bottom sheet 72xe2x80x2, upper and lower rows of tensile members 73xe2x80x2, a surrounding sheet 74xe2x80x2, upper and lower lateral sheets 76xe2x80x2, and a middle sheet 77xe2x80x2. The surrounding sheet 74xe2x80x2 has a top end that is heat-sealed to a periphery of the top sheet 71xe2x80x2, and a bottom end that is heat-sealed to a periphery of the bottom sheet 72xe2x80x2 . The middle sheet 77xe2x80x2 is disposed between the top and bottom sheets 71xe2x80x2, 72xe2x80x2, and has a periphery that is heat-sealed to the surrounding sheet 74xe2x80x2 so as to define upper and lower chambers in the bed 200xe2x80x2. The upper lateral sheets 76xe2x80x2 are heat-sealed respectively to two opposite sides of the lower end of the surrounding sheet 74xe2x80x2, while the lower lateral sheets 76xe2x80x2 are heat-sealed to two opposite sides of the bottom sheet 72xe2x80x2 so as to define an air chamber 202xe2x80x2 between each adjacent pair of the upper and lower lateral sheets 76xe2x80x2. The upper row of tensile members 73xe2x80x2 are heat-sealed to the top sheet 71xe2x80x2 and the middle sheet 77xe2x80x2. The lower row of tensile members 73xe2x80x2 are heat-sealed to the middle sheet 771 and the bottom sheet 72xe2x80x2. Although the material requirement for the bed 200xe2x80x2 is less than that for the bed 200 (see FIGS. 1 and 2), it is still difficult to manufacture the bed 200xe2x80x2 because the upper and lower rows of the tensile members 73xe2x80x2 are heat-sealed to the middle sheet 77xe2x80x2 in a staggered arrangement.
Therefore, the main object of the present invention is to provide an inflatable bed that is capable of overcoming the aforementioned drawbacks of the prior art.
According to the present invention, an inflatable bed is disposed on a support surface, and includes a plastic top sheet that has a top surface, a bottom surface, and an outer periphery. A plastic bottom sheet is disposed under the top sheet, and has a lower end that is adapted to be disposed on the support surface, and an outer periphery. A plastic partition is interposed between the top and bottom sheets, and has an outer periphery that is spaced apart from and that is disposed between the outer peripheries of the top and bottom sheets so as to be adapted to define a concave air bag among the bottom sheet, the partition, and the support surface. A plastic pull band unit is used to connect fixedly the bottom surface of the top sheet to an assembly of the bottom sheet and the partition. A plastic annular surrounding sheet is disposed around the top sheet, the bottom sheet, and the partition, and is connected fixedly to the outer peripheries of the top sheet, the bottom sheet, and the partition. An upper air chamber is defined among the top sheet, the partition, and the surrounding sheet, and is disposed above the concave air bag. An annular lower peripheral air chamber is defined among the partition, the surrounding sheet, and the bottom sheet, and is disposed around the concave air bag. An inflatable unit is operable so as to introduce air into the upper air chamber and the annular lower peripheral air chamber. As such, when a person moves onto the top surface of the top sheet, air is ejected from the concave air bag via a space between the bottom sheet and the support surface so that the bed acts as a suction cup, thereby fixing the bed relative to the support surface.